Reduced p21 expression in MIF-/- cells compared with wt. a. Levels of p21 expression in MIF-/- and wt MDF assessed by Western blotting using a monoclonal antibody to p21. The equivalence of protein loading was measured by detection of β-tubulin. Each lane represents a single MIF-/- or wt MDF mouse. b. Flow cytometric detection of p21 protein in untreated MDF taken from semi-confluent culture. Results are representative of 4 independent experiments, each measuring at least 5000 events. Expressed as delta mean fluorescence intensity (ΔMFI) which is the difference between the MFI of tested cells and the MFI of background staining (N = 4, * P < 0.05). c. Quantification of p21 mRNA to β-actin in MIF-/- and wt MDF by reverse transcription polymerase chain reaction (RT-PCR).